src/404.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Blur Admin</title>

  <link href='https://fonts.googleapis.com/css?family=Roboto:400,100,100italic,300,300italic,400italic,500,500italic,700,700italic,900italic,900&subset=latin,greek,greek-ext,vietnamese,cyrillic-ext,latin-ext,cyrillic' rel='stylesheet' type='text/css'>

  <link rel="icon" type="image/png" sizes="16x16" href="assets/img/favicon-16x16.png">
  <link rel="icon" type="image/png" sizes="32x32" href="assets/img/favicon-32x32.png">
  <link rel="icon" type="image/png" sizes="96x96" href="assets/img/favicon-96x96.png">

  <!-- build:css({.tmp/serve,src}) styles/404.css -->
  <!-- inject:css -->
  <!-- css files will be automatically insert here -->
  <!-- endinject -->
  <!-- endbuild -->
</head>
<body>
<div class="page-not-found-modal">
  <h1>404 Error</h1>

  <p>Sorry, that page doesn't exist. <a href="/">Go to Home Page.</a></p>
</div>
</body>
</html>